Reddish-brown dye.



Uixu rni) STATES PATENT -OFFICE He nz RG .AND OTTO HANsMAumor nEnLmcERMANY, AQ- SIGNORS'TO"THE AOTIIENTGESELLSOHAFT FUR ANILIN FABRIKATION,

on" SAME PLACE, 5.

REDIDI'SH-BROWNVDYE.

LS IECIIFICATION forming part of Letters Patent N 0. 657,065, dated August 28, 1900. Application filed June 28, 1900. Serial No. 21,987. ($pecimens.)

"lg'o dllq whom it 12mg} concern:

' V Be it known that we, WILHELM HERZBERG and Orro HANSMANN, of Berlin, in the Kingdom of Prussia, German Empire, have invented new and useful Improvements in the Production of Reddish Brown Dye; and we do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same. It 'is well known that for certain dyeing purposes it is necessary that the dyestuffs used should dye very uniformly and resist at the same time milling, soaping, the. As a rule the power to dye uniformly of coloringmatters depends upon a certain degree of solubility. On the other hand, increasing solubility in most cases is accompanied bya diminished fastness to milling and soaping. Hence it is of great technical importance to produce dyestufl's which possess both the valuable properties above referred to. Mordant-dyeing coloring-matters of an extraordinary fastness to milling-are obtained by combining diazotized. picramic acid with m'eta-diamins. (Compare German Patent No. 11?,819 of March 4, 1898, granted to the 1 \c'ti eu-Gese1lschaft fiirAnilin Fabrikation.) In order .to impart to them a greater power to, 'dye'uniformly, the nextway would be to increase their solubility by the introduction o'f acid radicals. However, the coloring-matters produced, for instance, by combining he diazo compound of picramic acid with tneta-diamin-sulfonic acids proved to be considerably less fast to milling. (e have now made the unexpected discovery that by starting-from chloro-meta-phenylenediamin (O1: NH :NH 1:3:5) a coloring-matter is obtained, the solubility and power to die uniformly of which is superior to those of the dyestuffs of German Patent No. 112,819, whilev its fastness to milling, soaping, &c.,

remains unchanged. Most probably in this case the chlorin atom acts as a weakly acid group, preventingthe salt of the dyestuif from being dissociated.

Our new dyestuft is extraordinarily fitfor all purposes for which combined fastness and power to dye uniformly are required. It is the more valuable as chloro-meta-phenylenediamin, (ChNH NH 1.: 3: 5,) is easily obtainable, and a product of but little cost.

To further illustrate our invention, we give the following directions: 22;4 kilos of sodium picramate are dissolved in water and twenty kilos of concentrated hydrochloric acid, (specifitfgravityequals 1.16.)Thesolutibn obtained is diazotized by means of 6.9 kilos of sodium nitrite. The diazo solution is allowed to run slowly into a solution of 14.5 kilos of chlorophenylenediamin (Cl :NH NH 1 :3: 5) and the mixture iswell stirred during several hours. 5.3 kilos of sodium carbonate are then added thereto, the liquid is heated, and the dyestuit is precipitated by means of common salt. The sodium salt of the dyestuif is soluble in water with reddish-yellow coloration, which on addition of sodium carbonate or caustic-soda lye remains unchanged. From the aqueous solution the dyestuif is precipitated by means of acetic acid in 1b form of brown flakes.

The dyestuft is hardly soluble in alcohol with red coloration. It dissolves easily in concentrated sulfuric acid, forming an orangered solution, which on addition of ice-water turns yellowish and on further dilution sep arates brown flakes.

The dyestuff dyes chromium-mordanted Wool' reddish-brown shades.

Having now described our invention and in what manner the same is to be performed, what we claim as new is-- The reddish-brown dye produced by combining diazotized picramic acid with chlorophenylenediamin (Cl NH NH 1: 3 :5); the sodium salt of said dye being soluble in water with reddish-yellow coloration, which on addition of sodium carbonate or causticsoda lye remains unchanged; the dye being precipitated from the aqueous solution by means of acetic acid in'the form of brown flakes; the dye being hardly soluble in alco- 'ange-red solution, which on addition of ice- Water turns yellow, on continued dilution sephol'with red ccloration; being easily soluble signed our ncmes, this 14th da y of J1me, 1900,

in concentrated sulfuric acid,-;f0rming an orin the presepce of two subscribing witnesses. w

WI-LHELM HERZBERG. mates brown flakes; the dye-producing on 01,110 M I chromium mordanfed wool reddish-brown Witnesses: shades. HENRY HASPER,

. In witness whereof we have hereunto WOLDEMAR HAUPT. 

